As the rapid development of communication technologies, a variety of network technologies emerge increasingly. The packet switching-based Next Generation Network (NGN) is becoming more and more popular among others. An NGN is a synthetic and fully-opened broad-frequency network platform architecture which may provide multiple services such as voice, data and multimedia simultaneously, and may implement at least Gigabit Fiber to the Home (FTTH). Moreover, the NGN may be used to introduce the low-price Internet Protocol (IP) telephony being used for long distance calls into local telephony, so as to decrease the cost and price of local calls greatly.
At present, the NGN includes a Signaling Proxy (SP) and a Media Proxy (MP) as shown in FIG. 1. Corresponding services may be provided in the NGN on the basis of the signaling proxy and the media proxy. The functionality of the signaling proxy and the media proxy is described as follows in detail.
For an NGN subscriber (designated as TE), the SP may be considered as a soft switching system. Registration and calling messages of the subscriber will be sent to the SP firstly, and be forwarded to a core soft switching system after suffering a signaling processing by the SP. For the core soft switching system, the SP may be considered as a subscriber. The soft switching system sends a request for calling a called subscriber to the SP, and then the SP forwards the request to the called subscriber after performing a signaling processing on the request. Generally the SP needs to support proxy functions for one or more of Session Initiation Protocol (SIP), H.323, Media Gateway Control Protocol (MGCP) and H.248.
The MP provides a proxy service for media flows. The media flows communicated between the subscriber and the outside are processed and forwarded through the MP. The media flow generally refers to a Real-time Transport Protocol (RTP) flow or a Real-time Transport Control Protocol (RTCP) flow.
In the NGN, a session table for the media flow processing is dynamically created/deleted on/from the MP by an SP instruction. The SP and the MP may communicate with each other via Common Open Policy Service (COPS) or a policy protocol in broad sense.
A relationship between the SP and the MP is described as follows in detail so that the NGN may be further understood.
Both the SP and the MP are a logical conception. One SP may communicate with one or more MPs. The SP and the MP may be integrated into one apparatus. The SP and the MP may also be implemented with independent apparatuses or integrated with other apparatuses respectively.
For the purpose of evaluating the capability of an NGN, in certain conditions it is required to obtain some attributes of the QoS of a session in the NGN such as Jitter and Delay.
However, there is no specialized method for obtaining QoS information of a session until now.